Swine flu outbreak

AP photo by Ng Han Guan

Chinese security guards wearing masks guard the entrance as a worker in protective garment disinfects the area outside a hotel used to quarantine students from the Nanhu Zhongyuan Primary School in Beijing, China. Students from the school were quarantined after some of them were diagnosed with swine flu on Wednesday.

Chinese security guards wearing masks guard the entrance as a worker in protective garment disinfects the area outside a hotel used to quarantine students from the Nanhu Zhongyuan Primary School in Beijing, China. Students from the school were quarantined after some of them were diagnosed with swine flu on Wednesday. (AP photo by Ng Han Guan)

A hotel was used to quarantine students from the Nanhu Zhongyuan Primary School in Beijing, China. The children were quarantined after some of them were diagnosed with swine flu on Wednesday.

A hotel was used to quarantine students from the Nanhu Zhongyuan Primary School in Beijing, China. The children were quarantined after some of them were diagnosed with swine flu on Wednesday. (AP photo by Ng Han Guan)

A swine flu outbreak, later identified as the H1N1 virus, began in Mexico and spread to the U.S., Canada, Switzerland, the Netherlands, New Zealand, Britain, Germany, Spain, Israel and Austria. Here is how the world responded to the outbreak.